Magnetic ore-separator



L. G. ROWAND.

MAGNETIC ORE SEPARATOR.

APPLICATIQN man suuzzx. m2.

1,303,396, Patent-ed May 13, 1919.

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L. G. ROWAND.

MAGNETIC ORE SEPARATOR.

'Arrucmou FILED was 21. 1911,

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L. G. ROWAND.

MAGNETIC ORE SEPARATOR.

APPLICATION man Jun; 21. m1.

Patented May13, 191.91

a SHEETS-SHEET 3i INVENTOR Z 610/5 6': Ron and EWIS e. nowAn'D, or BROOKLYN, :iTEW YORK, ASSIGNOR TO THE NEWaEnsEY ZINC UNITED sYrATEs PATENT o rron.

COMPANY, ornnw YORK, N; Y., A CORPORATION or NEW JERSEY.

MAGNETIC ORE-SEPARATOZR.

v Application filed .iune'21, 1917. Serial No. 176,027.

To all whom z't mdyconcem:

Be it known thatI, LEWIS G. RowAND, a

' citizen of the United States, residing at Sea declare the followingto' be a full, clear, and

exact description of the invent'iomsuch as will enable others skilled mule; art to which it appertains to makeja'nd use the same. The present. invention, relates to ore separators of the type in which the ore in finely divided condition is carried by a conveyer belt "into a' magnetic fieldwhich is so disposed as to lift the magnetic partiele'sout :of the gangue and against the bottom of another conveyer belt disposed at right angles to the ore conveyer and operatingvto divert these lifted magnetic. particles laterally with respect to the ore conveyer and finally discharge them intoa suitable receptacle. A separator of this general type is disclosed in U. S. Letters Patent No. 596,719, issued to me January 4, 1898.

It is an object. of the present invention to improve both mechanically and magnetically the structures whereby the electromagnetic field is set up and maintained.

It is a further object of the invention to so group the electromagnetic elements as to provide a plurality of magnetic. fields of differentintensity and, in fact, of different character, whereby, as I have found, a more advantageous separation of ore is obtainable, particularly in the case of certain zinc ores.

There are certain other object to be accomplished and certain inherent advantages in the apparatus of the present invention, all of which will be appreciated by those skilled in thisv art, and to the more important of which reference is particularly made in the following detailed description.

In the accompanying drawings Figure 1 is a side elevation of one em bodiment of the present invention;

Fig; 2 is a- 'l'a'n View of the same, certain of the under ying elements being omitted,

for the sake of clearness; t Fig. 3 s a transverse elevatlon on the hue 33 ofliigs. 1 and 2;

' Fig.4 is a transverse elevation on the line,

i H015 Figs; 1 and 2";

' channel.

Fig. 5 is a plan view on the horizontal secsp ecifi cati'on of Letters Patent. Patented lvlay 13; 1919.

tion 5-5 of Fig. 1, a part of the ore-carrying belt being broken ment's beneath;

Fig. 6. is a rear end elevation of paratus;

Fig. .7 is a horizontal section through the electromagnets on theline 77 of Fig. 4:;

away to disclose elethe ap- 8 is detail of the 1 -0 faces of these i l electromagnets; and F ig. .9 is a detail of one poleshoe. f v

In the embodiment illustratedftheinachine has for its foundation, girders land 2, each comprising a pair of channel irons arranged back to back and. spaced apart by a plurality of metal fittings .8 and .4 arranged in pairs. Bolts 5'hold the channels against these fittings. Theupper portion of 1 each fitting has a projecting shelf 6 which rests upon the upper flange of the adjacent Between each pair of fittings a standard or pedestal. 7 can be received and firmly clamped not only by the bolts 8,. provided for that purpose,but also by the bolts 5 which anchor the fittings to the channels. These pedestals are used. forsuppo-rtingeertain parts of the apparatus as hereinafter described more in detail. I

At the front end of the machine is a rec tangular framework 9, superimposed on which is a smaller fraineworklO, whereon is mounted the ore feeding hopperll. Ore from the hopper is fed in regulated amount by a feed roller suitably driven and for which no novelty is claimed herein, the ore being finally delivered to a substantially horizontal belt 12 of duck o-r othersuitable fabric, stretched rather tightly between cylindri-cal drums 13 and 14, one'of which is at the rear end of the machine and suitably driven, as by a belt pulley 15, and the other of which is'carried in a pair of bearings 16, each mounted to slide on a pair'of horizontal supporting bars 17. A counterweight 18 and a flexible tension band 19 serve, as shown in Fig. 1, to keep the ore carrying ery. to the-belt be traveling the same direction-as the belt and/at about the same speed. This is easily arranged for by adjustable deflectors and other like expedients well known in the art The electromagnetic device into the field or fields of which the ore is first transported by the conveyer belt has vertically disposed coils or windings 20 and 21 which are pro vided respectively with cylindrical iron cores 22 and 23 suspended by bolts from a magnetizable yoke 24. But in addition to the cylindrical cores on which the coils are controllable by a rheostat 30, and a similar rheostait 30 is in circuit with coil 21. The two coils 20 and 21 can, if desired, be connected in series, but I prefer that their circuits shall be independent so that I can, by suitable regulation of the current, make the magnetic flux or field between pole faces 27 and- 29- greater than that between pole faces 26 and 28. connected as not to neutralize one another, but on the contrary, to supplement one another in magnetizing the intermediate core 25, and the latter is'for this reason equal to or larger than the cross-section of the two adjacent cylindrical cores.

With windings 20 and 21 fully energized, there is a strong tendency for the pole faces to approach one another and a heavy lateral strain is thereby put on the bolts whereby the cores are supported. Any slight variation in the distance between adjacent pole pieces would, of course, have a pronounced effect on the magnetic field, and I therefore adequately protect the electromagnetic structure by abutments of wood introduced in each air gap. The Wood also keeps dirt out of the gap. In

Each abutment comprises a pair of wedgeshaped blocks 31 and 31, between which is interposed a flat strip 32. Vertical bolts 33, threaded into the pole tips, serve to hold the tapering blocks firmlyeag-ainst the in clined face of the metal pole and tightly wedged against the intervening fiat strip 32. The lower edge of this flat strip is flush with the bottom face of the pole tips, and by its presence gives asmooth bearing surface for the transverse belts hereinafter described. A wooden block 34, bolted to each wedge block, as shown in Fig. 7 gives greater security tothe structure, and a rounded face for the belt.

It is, of course, the function of this com- Coils-20 and 21 are of course so binedielectrom-agnet to lift from the upper face of the adjacent conveyer-belt the more 1 easily magnetizable particles or grains of the ore, and, if desired, the magnetic field between the pole faces'26 and 28 may be weaker than the magnetic field between pole faces27 and 29, thereby giving a selective action on particles which have different capacities for magnetization. As a means for receiving the particles and transporting them laterally for deposit in a suitable receptacle or chute, there is provided under each air gap of this electromagnetic unit 'a discharging belt 35.

by is conveyed atright angles to its previous path and ultimately is delivered into a hopper at the side of the main or ore conveying belt 12. j j

In the embodiment illustrated in Fig. 4, two hoppers are provided, a small one marked 41 being positioned just under the edge of the ore conveyerto collect such particles or grains of non-magnetic material as may become entangled with the truly magnetic material, and thereby diverted from the ore-laden belt. The truly magnetic material is, however, carried over into a larger hopper 42, or, at least is given such impetus in that direction that when released from the influence of the magnetic field, it falls therein. A hood 43 may be provided at the extreme outer end of this hopper to catch such particles as might otherwise be proj ected beyond the hopper. This hood can be pivotally mounted at 44 with a stud and wing nut to govern the distance of its front edge e from the adjacent conveyor and pulley.

As a means for prolonging the time during which the magnetizable particles are under the influence of the magnetic field,

and thereby insuring their delivery beyond the tangles hopper 41, I provide all four of the pole faces with a tapering lateral projection 45, somewhat after the principle disclosed in my above' identified Patent No. 596,719. There is, theref0re,a gradual diminution of the magnetic effect on the particle as it is moving laterally away from the electromagnet and into the receiving hopper, and with proper adjustment of conveyer speeds, electromagnetic strength and size and position of hoppers, there is no danger of a truly magnetizable particle dropping-back on; ore .conveyer-12 or into hopper 41. instead of into hopper .42. Forreasons which will now be apparent,

relativelyudefinite height above'the ore conveyer 12,-Yandto attainthis end, there is providedadrum or roller L6,(Fig. to sup-- ,rport the'orea'conveyerxat a definite height netic density above the .ore beltthan below underathc electromagnetic unit, and the unit 1 itselfIisradjustably supported. from above on a plurality of bolts .47. Anchoring lugsor jacks, indicated somewhat diagrammatically at 485 and .49 (Fig. 4,), may, by en agement with the verticalsteel support co umns 50 rand '51, serve to-steady' or anchor the. lower end 'of the electromagnetic unit;

each discharging belt35 has. its own pair of same sideof the'machine, even though the material gathered by onepair may be somewhat different; in grading from the material gathered by theother pair.

The mechanisms. above "described, while possessing the advantagesof 10w initial. cost,

high magnetic efiiciency and-the like, and While adequate fortaking from the finely divided ore mixture its more highly magnetic particles, does not, however, take fromj the charge, on the ore conveying belt all-of the-particles which are susceptible to mag netic influence; I thereforefind it expedient to provide another and more'powerful electromagnetic unit, and; sometimes more 5 than one,*which is positloned beyond. the

unit above' described and works on a different principle, and one more' nearly approaching the disclosure; of U. S. Letters PatentNo. 784,502,,issued to me on March In this second. electromagnetic unit and succeeding ones, if more, thanone is used,

Considering. more in detail this second electromagnetic unit,it may be described as comprising alower coil 52 with upstanding rectangular pole pieces 53 and 54 of generous cross-section over which the ore conveyer slides in passing from drum 13 to drum 1 1. Superimposed above coil 52 is a second andsiniilar coil 55 energized, if desired, by the same .current and having depending pole pieces 56 and 57, each ofwhich carries a removable rectangular pole point 58 (Fig. 9) seated in a recess in the pole I face, but havingone of its edgesopposed to the underlying fiat topped pole face of the lower coil and thereby giving a greater magit, and causing the inagnet'izable particles to lift out "of the gangue toward the edge of thisremovable pole point; With this driven from a I .as drum 60.

hoppers 41 and 42, and as both the belts 35 i can with convenience be, driven from the same pulley.39' (Fig.2), it istadvantageous -to have allwfour of" these hoppers on the I electromagnetic unit, each discharging belt 59 is carried on three drums 60, 61 and 62 I (Fig; 3),,drums 60 and62 being adjustable along studs 63 and 6-to compensate for stretching, and wear of the belt. Belt59 is The removable pole point 58 mayhave a tapering nose or tip 66,,as shown in Fig. 3, for the purpose .of graduating the release -of the'magnetized particle during its'travel with discharge belt 59.. This removable point may be held in position by bolts 67 (Fig. '9.) andmay be shod with .curved bronzefittings or shoes 68 and 69 to give a goo'd'xworkln'g curvature to discharge belt '59, and to prevent undue wear on the belt as it slides over the lower corner of the point. The pole point is so arranged that it can: be turned around in'its socket to present a, newworkingg edge whenever the old edge becomes so badly. worn as to require replacement. Vith this. electromagnetic unit, as with the one first described, there. may be a'small hopper YO-for the tangles and a large hopper 71 with. an adjustable hood--72 for the other deflected particles. h

Referring toFig. 5, it'w-ill be seen that all of the hoppers for the first electromagnetic unit. are on one side of the machine, and that for. the succeeding electromagnetic unit there is a: discharge, first to the right of the ore belt and. then to the left. Ihave found jthatwhen the ore goes under the first elecpulley 65 on the same. shaft tromagnetic unit, the entire charge is so-infiuenced by the magnets and the discharge belts that it shifts over to some extent on the ore conveyer, thereby giving. an unequal distribution of the remaining ore and gangue. I compensate for this by arranging ithenextx discharging belt to deliver to the other side of'the machine, thus pulling thegangueback to approximately an even distribution'on' the ore conveyer. The neXt discharge belt may properly be to the left of themachine as shown.

When coils 52 and 55 are connected in series, as shown, I prefer to control them by a pair of rheostats 73 and 74 (Fig. 5), one located on each side of the machine, but both beingconnected together by a single oper ating shaft so that on which ever side of the machine the operator may stand, hecan conveniently and with nicety adjust the magnetizing power of these combined'electromagnetizing coils.

With the coils fully magnetized,. there is of course an enormous pull of'one on the other, and to reliably keep. them apart and at justthe desired distance, I make use of supporting standardsand jacks. Thestandards 7, four in number, are adequately seand each of them carries a pair of nuts 75 between which is clamped one end of a'yoke I or frame 76 which may be of bronze, and

which supports one end of the lower coil 52 and its core and poles. f To the threaded upper end of each standard 7 is fitted a bronze cap 77 to serve as a jack and having its upper rounded end fitted to a bracket or frame 78 whereby the upper coil and its pole pieces are supported. The. weight of the upper coil and its adjuncts takes all slack. or backlash out of the joints and threads, and as the entire supporting structure is of generous proportions andrugged design, the presence or absence ofthe pow- -erful magnetic field between the pole pieces,

, the unit may, ifdesired, be less than the will'not appreciably change the air gap and an adjustment once'made can be relied on rrespective of manipulations of current strength.

With the arrangement above described, the air gap for: the second discharging belt of preceding air gap, for by manipulation of the jacks any one of the four supporting corners of the upper coil, can be raised or lowered to meet the exigencies of practical and illustrated in the drawings is one which has been used with success.

1. In a magnetic separator, the combination of an ore-conveying belt, an electromagnetic unit'positioned entirely above said beltqand having in its magnetic circuit a plurality of relatively narrow air gaps, the

field strength of each of which may be independently altered, and separate discharge Copies of this patent may be obtained at cured at their'lower ends as above described,

belts running'under each of said'airgaps' transversely oflsaid ore-conveying belt to laterally convey magnetic particles lifted from the ore-conveying belt at s'aid'air gaps.

2. In amagnetic separator, the combination of an ore-conveying; belt, aymagnetic I unit positioned entirely above said belt and comprising three magnetic poles spaced apart to form two relatively narrow air gaps and a pair of coils associated with'the magnetic poles for producing magneticfiux at the air gaps, means for separately controlling the energization of said coils to permit independent adjustment of the field strength of each of said air gaps, and separate discharge belts running transversely of said ore-conveying belt and positioned under each of said air gaps to laterally convey articles of ore lifted-from said ore-conveying belt at said gaps.

8. Ina magnetic separator, the combinationofan ore-conveying belt,' a magnetic unit-positioned above said belt and comprising a plurality of separate windings each with a magnetizable core cooperating with a central pole positioned betweensaid coils to form above said ore-conveying belt a pair of relatively. narrow magnetic air gaps,.the fieldv strength of eachof which may be independently altered, and discharge belts running transversely of said ore.-conveying belt and each positioned beneath an air gap to laterally convey magnetic particles lifted thereat.

4. In a magnetic separator, the combina-' tion of anxore-conveying means, an electromagnetic ore-lifting'unit positioned entirely above said means and comprising a pair of coils adapted to be independently controlled and each providedwith a magnetizable core,

a magnetizable pole magnetically cooperating with said cores and positioned between said coils to form a pair of elongated magnetic air gaps, the field strength of each of which may be'independen'tly altered, rigid spacers of non-magnetic material filling said gaps and holding said cores and intermediate pole in proper spacedrelation and discharging belts running transversely of said oreconveying" means and each positioned beneath one of the air gaps to laterally convey magnetic particles lifted thereat, substantially as described.

In testimony whereof I affix my signature.

LEWIS e. ROWAND.

five cents each, by addressing the Commissioner of Patents,

Washingtomlhfl. 

